Pen



FIG. 1 is a perspective view of a pen showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The stippling shown in the drawings represents the texture on the pen.

The broken-line showing of a portion of a writing instrument in the drawings is environmental matter and forms no part of the claimed design. The broken-line circle in FIG. 7 defines the bounds of the claimed design and forms no part thereof. 

The ornamental design for a pen, as shown and described. 